Currently, an Ethernet passive optical network (EPON) optical line terminal (OLT) optical module is generally a multi-channel sending and receiving optical component integrating an emitting channel and a receiving channel.
FIG. 1 exemplary shows a schematic structural diagram of an asymmetrical mode 10G EPON OLT. The schematic structural diagram includes a single optical fiber 10, a coaxial packaging distributed feedback laser (DFB) 11, a first filter 12, a coaxial packaging optical receiving component 13, a second filter 14, an external lens 15, an electro-absorption modulated laser (EML) 16, and a horizontal axis 17. The EML 16 is configured to emit a first downlink optical signal λ1, which is a 10 Gb/s convergent light, and the wavelength thereof is 1577±3 nm. The single fiber 10 and the EML 16 are disposed oppositely along the horizontal axis 17, which are configured to transmit at least one pair of uplink and downlink optical signals bidirectionally. The first filer 12 and the second filter 14 are located on the horizontal axis 17. The second filter 14 adjacent to the EML 16 is approximately 136° degree from the horizontal axis 17, and the first filter 12 adjacent to the fiber 10 is approximately 45° degree from the horizontal axis 17. The first downlink optical signal λ1 transmits through the second filter 14 and the first filter 12 in sequence and then converges to the fiber 10 for outputting. The coaxial packaging DFB 11 on one side of the horizontal axis 17 is configured to emit a second downlink optical signal λ2, which is a 1.25 Gb/s convergent light, and the wavelength thereof is 1490±20 nm. The optical signal is reflected to the first filter 12 after incoming to the second filter 14 converges to the fiber 10 for outputting after transmitting through the first filer 12. The single fiber 10 inputs a 1.25 Gb/s first uplink optical signal λ3, which has a wavelength of 1310±50 nm. After outgoing from the fiber 10, the first uplink optical signal λ3 incomes to the first filter 12, and reflected by the first filter 12, and then incomes to the coaxial packaging optical receiving component 13 on another side of the horizontal axis 17 for receiving.